Easy-to-open package having seal opening notch

ABSTRACT

An easily openable sealed package bag (P) is disclosed which hermetically seals a material to be packed (W), such as liquid, powder and viscous material, by longitudinally and laterally sealing three or four sides of a package film (F). A seal opening notch (N) comprising a cut is formed in a sealed portion (S) of the package bag (P) in such a way as to extend in a direction of depth of the sealed portion (S). The sealed portion (S) is also formed with a bent portion (B) adjacent to the seal opening notch (N). The easily openable sealed package bag is capable of enhancing the ease with which the package bag can be opened and the ease with which a seal opening portion can be identified by sight or by touch, without producing cut chips of the package bag. An apparatus for manufacturing such easily openable sealed package bags is also provided.

TECHNICAL FIELD

[0001] The present invention relates to an easily openable sealedpackage bag that can suitably be opened by breaking open a package filmas a packaging material with a finger tip and also to an apparatus formanufacturing the easily openable sealed package bags.

BACKGROUND OF THE INVENTION

[0002] A package bag has conventionally been made by vertically orlaterally sealing three or four sides of a package film made of apackaging material, such as a synthetic resin film or a laminatedmaterial formed by laminating the synthetic resin film and an aluminumfoil or the like. The package bag is filled with a material to bepacked, such as liquids, powders or viscous materials, before beinghermetically sealed.

[0003] To open the package bag, therefore, it is common practice to cuta sealed portion of the package film as the packaging material with aknife or scissors or break it open with a finger tip. When the packagebag is to be cut with a knife or scissors, the opening procedure istroublesome as it requires a tool. When the package film is to beruptured with a finger tip, the opening of the package film may not beaccomplished easily.

[0004] For these reasons, the package bag has recently been formed witha seal opening notch, which comprises a cut, at a sealed portion of thepackage bag to make it easy to break open the package bag. Two types ofopening notch are employed in general. For example, as shown in FIG. 12,a package bag P with its three sides sealed is formed with a simple cutor a so-called I-notch N1 at a sealed portion S. Alternatively, as shownin FIG. 13, a package bag P with its four sides sealed is formed with aso-called V-notch N2, which is formed by making a V-shaped cut, at asealed portion S. The opening notch is formed in the package bag P inthis way.

[0005] In making an opening notch, although the I-notch N1 offers theadvantage of simple manufacturing because of a simple shape of the cut,there is a drawback that, because the I-notch N1 is formed by making asimple cut at the sealed portion S of the package bag P, the edgeportion of the opening I-notch N1 is aligned with the side of the bagand may not be recognized easily, making it difficult to quickly locatethe position of the I-notch N1.

[0006] In this respect, the V-notch N2 which is a V-shaped cut is easilyrecognized because of its shape even by a person with failed eyesight.The use of the V-notch as an opening notch however is currently notapplied to food product packages in which materials W to be filled inthe package bag P are foods such as sauce, soup and soy sauce, becausewhen the V-notch N2 is to be formed in the sealed portion S of thepackage bag P, the sealed portion S of the package bag P needs to be cutin the shape of letter V during the notch forming process, producing cutchips which in turn may adhere to the product package bag P.

[0007] It is therefore an object of the invention to provide an easilyopenable sealed package bag which can improve the level of ease withwhich the package bag can be opened, without producing cut chips of thepackage bag, and which can enhance the level of ease with which theopening portion can be located with sight or feel. It is also an objectof the invention to provide an apparatus for manufacturing such aneasily openable sealed package bag.

DISCLOSURE OF THE INVENTION

[0008] In a package bag that hermetically seals a material to be packed,such as liquid, powder and viscous material, by longitudinally andlaterally sealing three or four sides of a package film, the packageaccording to the invention is characterized by: a seal opening notchcomprising a cut formed in a sealed portion of the package bag in such amanner as to extend in a direction of depth of the sealed portion; and abent portion formed in the sealed portion adjacent to the seal openingnotch comprising a cut. A resulting step formed by the bent portionallows the user to identify a seal opening notch position easily.

[0009] Further, the sealed portion of the package bag is formed with aseal opening notch comprising a cut which extends in a direction ofdepth of the sealed portion, and also with a bent portion (steppedportion) which extends from the deepest part of the seal opening notchcomprising a cut toward an outer edge of the sealed portion. Thisstructure easily forms a step at the edge portion where the notch iscut, making it possible to easily locate the notch portion comprising acut. Further, the configuration comprising the seal opening notch andthe bent portion (stepped portion) easily forms, by bending, a step withan almost V- or U-shaped width, thereby improving the ease with whichthe seal opening notch position can be distinguished by sight as well asby touch.

[0010] Further, in a packaging machine that continuously makes packagebags, the apparatus is characterized in that a notch forming mechanismis provided which has a pair of opposing rolls for clamping andtransporting the longitudinally sealed portion of the continuously fedpackage bags; and that a circumferential surface of at least one of theopposing rolls is formed with a protruding cutting edge that makes aseal opening notch comprising a cut in the longitudinally sealed portionof the package bags in such a way that the seal opening notch extends ina direction of depth of the longitudinally sealed portion, with theother roll functioning as a receiving roll, and the circumferentialsurface is also formed with a protruding bending edge that forms a bentportion in the longitudinally sealed portion adjacent to the sealopening notch. This construction provides an apparatus for manufacturingeasily openable sealed package bags that allow the user to identify theseal opening portion while preventing cut chips from being produced as aresult of making notches.

[0011] Further, in a packaging machine that continuously makes packagebags, the apparatus is characterized in that a notch forming mechanismis provided which has a pair of opposing rolls for clamping andtransporting the longitudinally sealed portion of the continuously fedpackage bags; that a circumferential surface of at least one of theopposing rolls is formed with a protruding cutting edge that makes aseal opening notch comprising a cut in the longitudinally sealed portionof the package bags in such a way that the seal opening notch extends ina direction of depth of the longitudinally sealed portion, with theother roll functioning as a receiving roll, and the circumferentialsurface is also formed with a protruding bending edge that extendscontinuously from the cutting edge at a position corresponding to thedeepest part of the seal opening notch toward an outer edge of thelongitudinally sealed portion in order to form a bent portion (steppedportion) in the longitudinally sealed portion; and that a height of atip of the bending edge is set slightly lower than a height of a tip ofthe cutting edge. This construction provides an apparatus formanufacturing easily openable sealed package bags that allow the user toidentify the seal opening portion while preventing cut chips from beingproduced as a result of making notches.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a perspective view showing an overall outline of afilling and packaging machine;

[0013]FIG. 2 is a front view showing an overall outline of the fillingand packaging machine of FIG. 1;

[0014]FIG. 3 is a perspective view showing a seal opening notch formingmechanism of FIG. 2;

[0015]FIG. 4 is a perspective view showing a cutting edge and a bendingedge, both essential parts of FIG. 3;

[0016]FIG. 5 is an outline cross section of the cutting edge and thebending edge of FIG. 4;

[0017]FIG. 6 is an explanatory view showing an example form of packagebag into which a package film is formed by a filling and packagingmachine according to one embodiment of the invention;

[0018]FIG. 7 is a perspective view of a package bag, an essentialportion of FIG. 6;

[0019]FIG. 8 is an essential-portion perspective view of a package bagaccording to one embodiment of the invention;

[0020]FIG. 9 is an essential-portion perspective view of a package bagaccording to another embodiment of the invention;

[0021]FIG. 10 is a perspective view of a package bag with its threesides sealed, as applied to the conventional apparatus and theinvention;

[0022]FIG. 11 is a package bag with its four sides sealed, as applied tothe conventional apparatus and the invention;

[0023]FIG. 12 is a front view showing an example of a conventionalpackage bag formed with an I-notch; and

[0024]FIG. 13 is a front view showing an example of a conventionalpackage bag formed with a V-notch.

BEST MODE FOR CARRYING OUT THE INVENTION

[0025] Now, one embodiment of the invention will be described byreferring to the accompanying drawings. An easily openable sealedpackage bag and the outline construction and operation of a filling andpackaging machine, which is an apparatus for manufacturing the easilyopenable sealed package bag with a package film, will be explained withreference to FIG. 1 through FIG. 7.

[0026] Referring to these figures, in the overall outline constructionof the filling and packaging machine, reference numeral 1 represents aframe of the filling and packaging machine, in the side portion of whichis provided a support frame 2 on which a roll R of film F is removablymounted.

[0027] The film F drawn out and guided from the film roll R is given apredetermined tension as it is guided through a film guide mechanism 3,and is then pulled upward to a film folding mechanism 4 disposed at theupper part of the frame 1 where the film is folded in two along itslength and from which the folded film is drawn downward and guided.

[0028] In this embodiment, the film F folded in two and drawn downwardis longitudinally heat-sealed at a folded edge portion, an intermediateportion and an opposite edge portion (at left and right edge portionsand an intermediate portion) by a pair of longitudinal heat seal rolls5A of a longitudinally sealing mechanism 5 to form longitudinally sealedportions S1. Then, a first laterally sealing mechanism 6 and a secondlaterally sealing mechanism 7, both disposed below the longitudinallysealing mechanism 5, laterally heat-seal the folded film to formlaterally sealed portions S2.

[0029] In this case, a pair of lateral heat seal rolls 6A of the firstlaterally sealing mechanism 6 laterally heat-seal the folded film atpredetermined intervals to form the laterally sealed portions S2. Thelaterally sealed portions S2 each form bottoms of bottomed cylinders,which will make two left and right parallelly arranged package bags. Thefilm F formed into a bottomed cylinder is filled with a material to bepacked W, which is supplied from filling nozzles 8A, 8B of a fillingmechanism 8. Then, after the film F is fed, the lateral heat seal rolls6A of the first laterally sealing mechanism 6 laterally heat-seal baginlet portions of the film F to form laterally sealed portions S2, whichseal the material to be packed W. These laterally sealed portions S2 arefurther sealed by a pair of lateral heat seal rolls 7A of the secondlaterally sealing mechanism 7 to seal four sides of the film F, and thepackage bags P thus formed are carried continuously downward in aconnected state.

[0030] In this kind of packaging machine, below the second laterallysealing mechanism 7 is arranged a seal opening notch forming mechanisms9, below which a perforation slitter mechanism 10 is disposed to formperforations in the center longitudinally sealed portion S1 of the leftand right parallel package bags P. Further blow the perforation slittermechanism 10 there is a cutting mechanism 11 that cuts the laterallysealed portions S2 of the vertically connected package bags P anddelivers the separated package bags P.

[0031] The seal opening notch forming mechanisms 9 are provided on bothedge sides of the left and right parallel package bags P. Each of theseal opening notch forming mechanisms 9 has a pair of opposing rolls 12,12A to form seal opening notches N in each of the longitudinally sealedportions S1 provided on the both edge sides of the parallel bags. A pairof the opposing rolls 12, 12A are arranged to clamp and transport thelongitudinally sealed portions S1 on the both edge sides of thecontinuously fed package bags P. On a circumferential surface of atleast one roll 12 of the opposing rolls is formed a protruding cuttingedge 13 that forms a seal opening notch N comprising a cut in thelongitudinally sealed portions S1 of the package bags P in such a waythat the notch extends in the direction of depth of the longitudinallysealed portions, with another roll 12A used as a receiving roll 12A. Atthe same time, the circumferential surface of at least one roll 12 isformed with a protruding bending edge 13A that extends continuously fromthe cutting edge 13 at a position corresponding to the deepest part ofthe seal opening notch N toward the outer edge of the longitudinallysealed portions S1 in order to form a bent portion B (stepped portion)in the longitudinally sealed portions S1. Further, as shown in FIG. 7,the height L2 of the tip of the bending edge 13A is set slightly lowerthan the height L1 of the tip of the cutting edge 13 so that the bentportion B (stepped portion) can be obtained in the longitudinally sealedportions S1.

[0032] In the embodiment described above, the filling and packagingmachine that continuously forms package bags is characterized in thatthe seal opening notch forming mechanisms 9 are provided that each havea pair of the opposing rolls 12, 12A for clamping and transporting thelongitudinally sealed portions S1 of the continuously fed package bagsP; that the circumferential surface of at least one roll 12 of theopposing rolls is formed with the protruding cutting edge 113 that formsthe seal opening notch N comprising a cut in the longitudinally sealedportions S1 of the package bags P in such a way that the notch extendsin the direction of depth of the longitudinally sealed portions, withanother roll 12A used as a receiving roll 12A, and the circumferentialsurface of at least one roll 12 is also formed with a protruding bendingedge 13A that extends continuously from the cutting edge 13 at aposition corresponding to the deepest part of the seal opening notch Ntoward the outer edge of the longitudinally sealed portions S1 in orderto form a bent portion B in the longitudinally sealed portions S1; andthat the height L2 of the tip of the bending edge 13A is set slightlylower than the height L1 of the tip of the cutting edge 13. With thisconstruction, the cutting edge 13 formed on the surface of one roll 12and the circumferential surface of the receiving roll 12A or the otherroll engage each other, clamping the longitudinally sealed portions S1of the package bags P between the cutting edge 13 and thecircumferential surface of the receiving roll 12A or the other roll,thus making a cut in the longitudinally sealed portions S1. As a result,a seal opening notch N is formed, which is a cut extending from theouter edge of the longitudinally sealed portions S1 in the direction oftheir depth. At the same time, because of the height L2 of the tip ofthe bending edge 13A being slightly lower than the height L1 of the tipof the cutting edge 13, the bending edge 13A clamps the longitudinallysealed portions S1 of the package bags P between it and the roll 12Aand, by the clamping stress, deforms the longitudinally sealed portionsS1 and bends that normally flat part of the longitudinally sealedportions S1 against which the bending edge 13A is pressed, thusirregularly shaping the edge portions where the seal opening notches Nare cut.

[0033] As a result, the longitudinally sealed portions S1 of the packagebags P are formed with the seal opening notches N, which are cutsextending from the outer edges of the longitudinally sealed portions S1in the direction of their depth, as described above. At the same time,the bent portions B that extend from the deepest part of the sealopening notches N toward the outer edges of the longitudinally sealedportions S1 are formed by deformation. The edge portions where the sealopening notches N are cut are made irregular by the bent portions thatare formed by deformation. The irregular stepped portion allows the userto easily recognize by sight that this is a seal opening location of thepackage bag P. Further, by touching the bent portion B with a fingertip, the user can feel a dent or bulge at the bent portion and decidethat the irregular part is the seal opening location of the package bagP.

[0034] As shown in FIG. 7, because the seal opening notch N and the bentportion B which extends from the deepest part of the seal opening notchN or cut toward the outer edge of the longitudinally sealed portion S1are formed in the longitudinally sealed portion S1 in the shape ofletter V, a stepped portion with a V-shaped width, defined by the sealopening notch N and the bent portion B, is easily formed by bending,thus improving the ease with which the seal opening notch N can beidentified by sight as well as by touch.

[0035] In the embodiment as described above, because the seal openingnotch N1, which comprises a cut, is formed in the longitudinally sealedportion S1 of the package bag P in such a manner as to extend in thedirection of its depth, the cut chips can be prevented from being formedas they would when the conventional notch is cut. Further, because thebent portion B is formed in the longitudinally sealed portion S1 in sucha way as to extend from the deepest part of the seal opening notch N1 orcut toward the outer edge of the longitudinally sealed portion S1, aneasily openable sealed package bag can be provided that allows easyidentification of the seal opening portion.

[0036] Further, to obtain a package bag P according to one embodimentshown in FIG. 7, the filling and packaging machine that continuouslyforms package bags is characterized in that the surface of a roll isformed with the protruding cutting edge 13 that forms a seal openingnotch N comprising a cut in the longitudinally sealed portions S1 of thepackage bags P in such a way that the notch extends in the direction ofdepth of the longitudinally sealed portions; that the roll surface isalso formed with the protruding bending edge 13A that extendscontinuously from the cutting edge 13 at a position corresponding to thedeepest part of the seal opening notch N toward the outer edge of thelongitudinally sealed portions S1 in order to form the bent portion B inthe longitudinally sealed portions S1; and that the height L2 of the tipof the bending edge 13A is set slightly lower than the height L1 of thetip of the cutting edge 13. With this construction it is possible toprovide an easily openable sealed package bag that allows easyidentification of the seal opening portion while preventing cut chipsfrom being produced as a result of making notches. In the embodiment,the geometry comprising the cutting edge 13 and the bending edge 13A ofthe seal opening notch forming mechanism 9 in the packaging machine isset according to the nearly V-shaped configuration comprising the sealopening notch N and the bent portion B.

[0037] In an embodiment of the package bag P as shown in FIG. 8, theseal opening notch N, which is a cut extending in the direction of depthof the longitudinally sealed portion S1 of the package bag P, and thebent portion B, which extends from the deepest part of the seal openingnotch N or cut toward the outer edge of the longitudinally sealedportion S1, are formed virtually like a letter U in the longitudinallysealed portion S1. In this case, too, as in the V-shaped configuration,because a stepped portion with an almost U-shaped width, defined by theseal opening notch N and the bent portion B, is formed by bending, thestepped portion improves the ease with which the seal opening notch Ncan be located by sight as well as by touch. The geometries of thecutting edge and the bending edge of the seal opening notch formingmechanism 9 need to be set according to the virtually U-shapedconfiguration comprising the seal opening notch N and the bent portionB.

[0038] Further, in another embodiment of the package bag P as shown inFIG. 9, the longitudinally sealed portion S1 of the package bag P isformed with a seal opening notch N, which comprises a cut, extending inthe direction of depth of the longitudinally sealed portion S1 and witha bent portion B adjacent to the seal opening notch N or cut. In thisembodiment, because the seal opening notch N is surrounded by thesemicircular bent portion B, the bent portion B provides a steppedportion around the seal opening notch N in the normally flat,longitudinally sealed portion S1. This enables the seal opening portionto be easily located. The geometries of the cutting edge and the bendingedge of the seal opening notch forming mechanism 9 in the packagingmachine need to be set according to the configuration of the sealopening notch N and the bent portion B. This can be achieved by settingthe height of the tip of the bending edge slightly lower than the heightof the tip of the cutting edge.

[0039] In the embodiments described above, an example case has beenexplained in which a sheet of film F is drawn out in a two-foldedcondition and guided, and in which the folded edge part of the foldedfilm, the central part of the folded film F and the opposite edge part(left and right edge parts and the central part) are longitudinallyheat-sealed by a pair of three longitudinal heat seal rolls 5A to formtwo columns of cylindrical package bags P. Other forms of easilyopenable sealed package bag can be made by forming the seal openingnotch of the invention in the sealed package bag. For example, as shownin FIG. 10, the film F may be sealed at three sides of the package bagP; or, as shown in FIG. 11, two sheets of film F may be overlapped,drawn out and guided, and the film F sheets may be longitudinallyheat-sealed along their both edges by two longitudinal heat seal rollswhile at the same time heat-sealing four sides of the films F to formthe package bags P; or, though not shown, a number of longitudinal heatseal rolls may be provided at longitudinal seal portions, and thelongitudinal heat seal rolls and the lateral seal portions may becombined to form a number of four-side-sealed package bags in eachlateral row; or, the package bags may be sealed individually.

[0040] In the easily openable sealed package bag according to theinvention, because a seal opening notch N or cut is formed in the sealedportion of the package to extend in the direction of depth of the sealedportion and a bent portion is formed in the sealed portion adjacent tothe seal opening notch or cut, a step formed by the bent portion makesthe seal opening notch easily identifiable.

[0041] Further, because the sealed portion is formed with a seal openingnotch or cut extending in the direction of depth of the sealed portionof the package bag and also with a bent portion extending from thedeepest part of the seal opening notch or cut toward the outer edge ofthe sealed portion, a step is easily formed at the outer edge portionwhere the cut is made, allowing the notch portion or cut to be easilydistinguished. At the same time, the combined configuration of the sealopening notch and the bent portion easily forms a step with an almost V-or U-shaped width as a result of bending. This in turn improves the easewith which the seal opening notch can be located by sight as well as bytouch.

[0042] Further, the packaging machine that continuously makes packagebags is characterized in that a notch forming mechanism is providedwhich comprises a pair of opposing rolls for clamping and transportingthe longitudinally sealed portions of the package bags beingcontinuously fed; that the circumferential surface of at least one ofthe opposing rolls is formed with a protruding cutting edge that makes aseal opening notch or cut in the longitudinally sealed portion of thepackage bag in such a way that the notch extends in the direction ofdepth of the longitudinally sealed portion, with the other rollfunctioning as a receiving roll, and the circumferential surface is alsoformed with a protruding bending edge that makes a bent portion adjacentto the seal opening notch in the longitudinally sealed portion; and thatthe height of the tip of the bending edge is set slightly lower than theheight of the tip of the cutting edge. This construction can provide anapparatus for manufacturing the easily openable sealed package bag thatenables the seal opening portion to be easily located while preventingcut chips from being produced as a result of making cuts.

[0043] Further, the packaging machine that continuously makes packagebags is characterized in that a notch forming mechanism is providedwhich comprises a pair of opposing rolls for clamping and transportingthe longitudinally sealed portions of the package bags beingcontinuously fed; that the circumferential surface of at least one ofthe opposing rolls is formed with a protruding cutting edge that makes aseal opening notch or cut in the longitudinally sealed portion of thepackage bag in such a way that the notch extends in the direction ofdepth of the longitudinally sealed portion, with the other rollfunctioning as a receiving roll, and the circumferential surface is alsoformed with a protruding bending edge that extends continuously from thecutting edge at a position corresponding to the deepest part of the sealopening notch toward the outer edge of the longitudinally sealed portionin order to form the bent portion in the longitudinally sealed portion;and that the height of the tip of the bending edge is set slightly lowerthan the height of the tip of the cutting edge. This construction canprovide an apparatus for manufacturing an easily openable sealed packagebag that can prevent cut chips from being produced as a result of makingcuts and which can easily form a step at the edge portion where thenotch is cut, thus allowing the notch or cut portion, i.e., the sealopening portion, to be easily located.

INDUSTRIAL APPLICABILITY

[0044] In making easily openable sealed package bags that can suitablybe opened by breaking open a package film or a packaging material with afinger tip, the invention provides an easily openable sealed package bagthat can improve the ease with which the package bag can be opened andthe ease with which the seal opening portion can be located by sight orby touch, without producing cut chips of the package bag. The inventionalso provides an apparatus for manufacturing such a package bag.

1. In an easily openable sealed package bag which hermetically seals amaterial to be packed, such as liquid, powder and viscous material, bysealing a package film at three or four sides thereof vertically andhorizontally, the easily openable sealed package bag characterized by: aseal opening notch comprising a cut and formed in a sealed portion ofthe package bag to extend in a direction of depth of the sealed portion;and a bent portion formed in the sealed portion adjacent to the sealopening notch comprising a cut.
 2. An easily openable sealed package bagaccording to claim 1 , wherein the seal opening notch comprising a cutis formed in the sealed portion of the package bag to extend in adirection of depth of the sealed portion, and the bent portion is formedin the sealed portion to extend from the deepest part of the sealopening notch comprising a cut toward an outer edge of the seal portion.3. An easily openable sealed package bag according to claim 2 , whereina geometry comprising the seal opening notch and the bent portion isshaped like a letter V or U.
 4. In a packaging machine which performsthe steps of: longitudinally sealing a continuously fed package film bya longitudinally sealing mechanism to form the package film into acylindrical shape by longitudinally sealed portions, laterally sealingthe cylindrically shaped package film by a laterally sealing mechanismto form bottom portions of package bags by laterally sealed portions,filling a material to be packed into the package film that was formedinto a bottomed cylindrical shape by the bottom portions, and laterallysealing an inlet side of the package film by the laterally sealingmechanism while feeding the package film, thus continuously makingpackage bags; an apparatus for manufacturing easily openable packagebags characterized by: a notch forming mechanism having a pair ofopposing rolls for clamping and transporting the longitudinally sealedportion of the continuously fed package bags; wherein a circumferentialsurface of at least one of the opposing rolls is formed with aprotruding cutting edge that makes a seal opening notch comprising a cutin the longitudinally sealed portion of the package bags in such a waythat the seal opening notch extends in a direction of depth of thelongitudinally sealed portion, with the other roll functioning as areceiving roll, and the circumferential surface is also formed with aprotruding bending edge that forms a bent portion in the longitudinallysealed portion adjacent to the seal opening notch; wherein a height of atip of the bending edge is set slightly lower than a height of a tip ofthe cutting edge.
 5. In a packaging machine which performs the steps of:longitudinally sealing a continuously fed package film by alongitudinally sealing mechanism to form the package film into acylindrical shape by longitudinally sealed portions, laterally sealingthe cylindrically shaped package film by a laterally sealing mechanismto form bottom portions of package bags by laterally sealed portions,filling a material to be packed into the package film that was formedinto a bottomed cylindrical shape by the bottom portions, and laterallysealing an inlet side of the package film by the laterally sealingmechanism while feeding the package film, thus continuously makingpackage bags; an apparatus for manufacturing easily openable packagebags characterized by: a notch forming mechanism having a pair ofopposing rolls for clamping and transporting the longitudinally sealedportion of the continuously fed package bags; wherein a circumferentialsurface of at least one of the opposing rolls is formed with aprotruding cutting edge that makes a seal opening notch comprising a cutin the longitudinally sealed portion of the package bags in such a waythat the seal opening notch extends in a direction of depth of thelongitudinally sealed portion, with the other roll functioning as areceiving roll, and the circumferential surface is also formed with aprotruding bending edge that extends continuously from the cutting edgeat a position corresponding to the deepest part of the seal openingnotch toward an outer edge of the longitudinally sealed portion in orderto form a bent portion in the longitudinally sealed portion; wherein aheight of a tip of the bending edge is set slightly lower than a heightof a tip of the cutting edge.